Goss - Quick and Easy server validation

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Goss in 45 seconds

Note: For an even faster way of doing this, see: autoadd

Note: For some Docker usecases, see my blog post here and dockerhub repo

Introduction

What is Goss?

Goss is a YAML based serverspec-like tool for validating a server’s configuration. It eases the process of writing tests by allowing the user to generate tests from the current system state. Once the test suite is written they can be executed, waited-on, or served as a health endpoint.

Why use Goss?

• Goss is EASY! - Goss in 45 seconds
• Goss is FAST! - small-medium test suits are near instantaneous, see benchmarks
• Goss is SMALL! - <10MB single self-contained binary

Installation

# Install latest version to /usr/local/bin
curl -fsSL https://goss.rocks/install | sh

# Install v0.2.3 version to ~/bin
curl -fsSL https://goss.rocks/install | GOSS_VER=v0.2.3 GOSS_DST=~/bin sh

Manual installation

# See https://github.com/aelsabbahy/goss/releases for release versions
curl -L https://github.com/aelsabbahy/goss/releases/download/_VERSION_/goss-linux-amd64 -o /usr/local/bin/goss
chmod +rx /usr/local/bin/goss

Full Documentation

Documentation is available here: https://github.com/aelsabbahy/goss/blob/master/docs/manual.md

Quick start

Writing a simple sshd test

An initial set of tests can be derived from the system state by using the add or autoadd commands.

Let's write a simple sshd test using autoadd.

# Running it as root will allow it to also detect ports
$ sudo goss autoadd sshd

Generated goss.yaml:

$ cat goss.yaml
port:
  tcp:22:
    listening: true
    ip:
    - 0.0.0.0
  tcp6:22:
    listening: true
    ip:
    - '::'
service:
  sshd:
    enabled: true
    running: true
user:
  sshd:
    exists: true
    uid: 74
    gid: 74
    groups:
    - sshd
    home: /var/empty/sshd
    shell: /sbin/nologin
group:
  sshd:
    exists: true
    gid: 74
process:
  sshd:
    running: true

Now that we have a test suite, we can:

• Run it once

goss validate
...............

Total Duration: 0.021s # <- yeah, it's that fast..
Count: 15, Failed: 0

• keep running it until the system enters a valid state or we timeout

goss validate --retry-timeout 30s --sleep 1s

• serve the tests as a health endpoint

goss serve &
curl localhost:8080/healthz

# JSON endpoint
goss serve --format json &
curl localhost:8080/healthz

Patterns, matchers and metadata

Goss files can be manually edited to match:

• Patterns
• Advanced Matchers.
• title and meta (arbitrary data) attributes are persisted when adding other resources with goss add

Some examples:

user:
  sshd:
    title: UID must be between 50-100, GID doesn't matter. home is flexible
    meta:
      desc: Ensure sshd is enabled and running since it's needed for system management
      sev: 5
    exists: true
    uid:
      # Validate that UID is between 50 and 100
      and:
        gt: 50
        lt: 100
    home:
      # Home can be any of the following
      or:
      - /var/empty/sshd
      - /var/run/sshd

package:
  kernel:
    installed: true
    versions:
      # Must have 3 kernels and none of them can be 4.4.0
      and:
      - have-len: 3
      - not:
          contain-element: 4.4.0

Supported resources

• package - add new package
• file - add new file
• addr - add new remote address:port - ex: google.com:80
• port - add new listening [protocol]:port - ex: 80 or udp:123
• service - add new service
• user - add new user
• group - add new group
• command - add new command
• dns - add new dns
• process - add new process name
• kernel-param - add new kernel-param
• mount - add new mount
• interface - add new network interface
• http - add new network http url
• goss - add new goss file, it will be imported from this one

Supported output formats

• rspecish (default) - Similar to rspec output
• documentation - Verbose test results
• JSON - Detailed test result
• TAP
• JUnit
• nagios - Nagios/Sensu compatible output /w exit code 2 for failures.

Community Contribuations

• goss-ansible - Ansible module for Goss
• kitchen-goss - A test-kitchen verifier plugin for GOSS
• goss-fpm-files - Might be useful for building goss system packages

Limitations

Currently goss only runs on Linux.

The following tests have limitations.

Package:

• rpm
• deb
• Alpine apk
• pacman

Service:

• systemd
• sysV init
• OpenRC init
• Upstart